RE: Voice Traffic

Kazi,

Unless your voice gateway is hairpinning all calls for the endpoints, this
isn't likely going to match all your RTP streams. You've described the MPLS
router config, can you describe the voice application now? Is this a Cisco
solution? A typical smaller scale solution would involve voice servers and
endpoints in the same /24 or /23; you want to match on that range if you would
prefer the method listed below. I try to match on DSCP markings of 46 since
the switches and endpoints are under my control; phones are set to remark any
packets to 0 from their PC port and the switches are set to trust CoS and map
CoS 5 to DSCP 46.

You probably want to shape to your MPLS providers circuit speed and setup a
parent child QoS policy-map as was recommended earlier. Apply your LLQ policy
to the child.

http://www.cisco.com/en/US/tech/tk543/tk545/technologies_tech_note09186a00801
14326.shtml

-ryan

From: Kazi Junaid [mailto:junaidkazi76_at_gmail.com]
Sent: Sunday, September 05, 2010 7:23 PM
To: Ryan West
Cc: karim jamali; Cisco certification
Subject: Re: Voice Traffic

Hi,

Does this looks ok?

Voice_Gateway : 10.255.1.100/24<http://10.255.1.100/24>
access-list 100 permit udp host 10.255.1.100 any range 16384 32767

class-map match-all VG
match ip access-group 100

policy-map VG
class VG
priority percentage 60
class class-default
fair-queue

int f 0/0.99
service-policy output VG

On Mon, Sep 6, 2010 at 2:20 AM, Ryan West
<rwest_at_zyedge.com<mailto:rwest_at_zyedge.com>> wrote:
Kazi,

> -----Original Message-----
> From: nobody_at_groupstudy.com<mailto:nobody_at_groupstudy.com>
[mailto:nobody_at_groupstudy.com<mailto:nobody_at_groupstudy.com>] On
> Behalf Of karim jamali
> Sent: Sunday, September 05, 2010 7:05 PM
> To: Kazi Junaid; Cisco certification
> Subject: Re: Voice Traffic
>
> Hi Kazi,
>
> I guess you are looking for LLQ solution and what it does is the following:
> 1.Gives priority to voice traffic by putting it inside a priority queue
which gets
> serviced first.
> 2.You wouldn't want your voice traffic to kill other applications, thus you
will
> need to put an upper limit to this prioritized traffic, i.e. you are saying
I will
> guarantee voice is service first with an upper limit of 1Mbps, if this limit
is
> exceeded, well it depends on how the link is doing, if it is fine than than
you
> will still have it working perfectly, if the link is congested, you are
only
> guaranteed up to 1Mbps of excellent service, more than that you will lose
> the guarantee.
>
> Steps:
> 1.You will need to match the traffic which I guess is the RTP (udp 16384
> 32767)
Assuming this a standards based VoIP solution, you could match on protocol RTP
audio, DSCP 40/46, or ACL that specifies voice IP ranges and the UDP range
listed above.

However, above this all this, you need to work with your MPLS provider to
ensure they are treating your voice as a gold/real-time/insert your favorite
most expensive marketing term for priority traffic here. You can queue
outbound as much as like, but if your provider isn't doing the same it could
be in vain

For LLQ:

http://www.cisco.com/en/US/docs/ios/12_2/qos/configuration/guide/qcfwfq_ps183
5_TSD_Products_Configuration_Guide_Chapter.html#wp1022204

From a carrier's perspective:

http://www.google.com/url?sa=t&source=web&cd=1&ved=0CBIQFjAA&url=http%3A%2F%2
Fwww.globalcrossing.com%2Fdocs%2Fipkc%2Fmpls_qos.ppt&ei=ViWETOjLB4L88Abs_6nzA
Q&usg=AFQjCNGr2ego_xozF_67wXLO7RUwGVrmWw

-ryan

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Received on Sun Sep 05 2010 - 23:35:39 ART